It is the general purpose of a folding drum to temporarily convey a product, which is to be folded in a folder, and to push the product into a folding jaw of a folding jaw cylinder in an orientation suitable for folding, or, depending on the type of the folder, to transfer the product to two folding rollers, which two folding rollers draw the product, with the desired fold line at the front, into a gap formed between them and to thus fold the product in this way. The folding drum has a plurality of movable folding blades for accomplishing this purpose, which movable folding blades can be extended through openings in a shell of the folding drum in order to insert the product to be folded into a folding jaw or into a gap between two folding rollers.
The extending and retracting movement of the folding blade is coupled to the rotation of the folding drum by the use of a gear. Folders are known, wherein the coupling can be cancelled for one of the two folding blades in the folding drum, and the folding blade can be stopped. This stoppage of one of the folding blades allows for so-called collection production. A product can be transferred to the folding drum at a transfer point and can make a complete revolution on the folding drum without being pushed off by a folding blade. When the product again passes the transfer point, a second product is placed on top of the first one, and both products are moved on together by the folding drum. If now both products are pushed off together by the folding blade, they are folded together.
DE 195 11 054 C2 discloses a drive mechanism for a folding blade of a folding drum. Driving of the folding blade is provided via a central gear wheel.
DE 12 22 082 B1 describes a wheel folder, whose folding blades can be adjusted by an adjusting gear via an axially displaceable gear wheel.
A folding drum of a folder with a folding blade arranged on a support is known from GB 1 059 158 A. A gear wheel, which is arranged coaxially with respect to the axis of rotation of the support is provided, which gear wheel, in one mode of operation, has a number of revolutions which is different from that of the folding drum.